Computing devices often exchange messages with one another over publicly-accessible networks. To keep the messages secure, a sending computer can encrypt a message using a key, and, if a receiving computer also has a key, the receiving computer can decrypt the message.
Encryption may be applied to data other than messages between computing devices. For example, data may be stored in distributed ledgers such as blockchains, where each block in a distributed blockchain includes an immutable and mutually agreed upon record of a transaction. At least a portion of data in one or more blocks can be secured using a public/private key combination.